Collecting Seed

[floraldi]

There are some seeds I really want to save for next year and others for giving away. I have noticed in the past that some seeds don't seem to be productive when they have been saved e.g. Bidens. 

Has anyone got any tips?  With the Welsh Poppy which I have saved a lot of they are dry and easy but the Bidens has only just lost it's petals and I wondered if I need to dry them in some special way.

[floraldi]

[Eristic]

Never done Bidens but seeds must be mature before harvesting whatever they are.

[allaboutliverpool]

What is a Biden?

[floraldi]

Sorry, not been around for a week. Bidens is a plant that is used a lot in those huge baskets the councils do.  It makes a large branching plant with many yellow small daisy type flowers.